If you remember the privacy fiasco that Firesheep caused just months ago by allowing laptop-toting pranksters to hijack the Facebook accounts of unwitting public Wi-Fi users, then you'll know the sort of tom-foolery that's about to ensue now that FaceNiff exists. The app allows Android phones to sniff out and use Facebook accounts of other users on the same open wireless network with a single tap of the finger. This time, however, there's no bulky laptop involved, making the deed easier to perpetrate than ever before.